。
She can play the drums.
Literal
She [topic-は] drums hit can.
Japanese pairs musical instruments with highly specific verbs: drums get 叩く (hit), guitar and piano get 弾く (pluck/strike), flutes and woodwinds get 吹く (blow), and so on. Asking '楽器を弾けますか?' subtly excludes percussion and wind. The を after ドラム is dropped here, common in casual speech. ことができる is the textbook 'can do' construction, slightly more formal than the potential form 叩ける would be.